Re: FreeBSD-HEAD gets stuck on vnode operations

On 26/05/13 22:20, Jilles Tjoelker wrote:
> Instead of a pause() that may be too short or too long, how about
> waiting for the necessary lock? In other words, replace the kern_yield()
> call with VI_LOCK(vp); VI_UNLOCK(vp);. This is also the usual approach
> to acquire two locks without imposing an order between them.

Since there might be more than one locked vnode, waiting on a specific
locked vnode seemed rather arbitrary, but I agree that the pause is also
rather arbitrary.

Also, can we be sure that the v_interlock mutex will not be destroyed
while the syncer process is waiting for it to be unlocked?

> I expect blocking on a mutex to be safe enough; a mutex may not be held
> across waiting for hardware or other events.
>